Sense Number 2: a serving of food, a piece

Examples:
Will you have another slice of peach pie?
Bob ate the last slice of pizza.
Take slices of bread and butter both sides.
The film is a slice of life. (figurative extension)

Mappings:WordNet 3.0 Sense Numbers: 2

Sense Number 3: a narrow, deep cut on something

Commentary: SLICE[+entity][+structure][+opening][+cut][+narrow]

Examples:
The surgeon made a four-inch slice across the patient's lower abdomen.
John got a nasty slice on his leg from the cat scratching him.
Betty made several slices in the top pie crust before putting it into the oven.

Sense Number 4: a golf shot that curves inadvertently

Sense Number 5: flat thin pieces of something

Commentary: SLICE[+form][+flat][+thin][+piece][+whole]

Examples:
The pathologist looked at small slices of the tissue under a microscope.
The jeweler made vertical slices of the gemstones with a laser.
Lay the slices of dough across the pie in a crisscross fashion. (Note: -not- a serving of dough (sense 2), but a structurally useful bit of it)